The present invention relates to an air conditioner for automobiles and, more particularly, to a control apparatus of an automatic air conditioner for automatically controlling a room temperature.
For example, as shown in Japanese Patent Unexamined Publication No. 59-70218, in the conventional automatic air conditioner, as shown in FIG. 5, the temperature of the blowout air from the air conditioner is controlled on the basis of a room set temperature T.sub.S, an insolation amount Z.sub.c, an outside air temperature T.sub.a, and the like so as to make an actual room temperature T.sub.R coincide with a room target temperature T.sub.so by calculating the room target temperature T.sub.so as the optimum room temperature under those outside air temperature and insolation amount.
In such a conventional automatic air conditioner, the very comfortable temperature control can be realized in the air conditioning of a wide space such as in a building. However, there is a drawback such that the comfortable temperature control cannot be always derived in the air conditioning of the narrow room of an automobile. This drawback is caused because of the following conditions which are peculiar to the rooms of automobiles.
(1) The room space of the automobile is very narrow and the blowout port of the air conditioner is arranged at the position which is very close to the body of the passenger (including the driver). Thus, the temperature distribution in the whole room is not uniform and the ratio that the passenger directly receives the blowout air from the air conditioner is high.
(2) Under the condition of a large heat load such as in the summer season, winter season, or the like, the incident amount or radiation amount of the heat through window glasses and the like is very large and the temperature gradient in the room is large. (For example, under the condition of the summer season, although the side surface of the body of the passenger on the window glass side is hot, the side surface on the opposite side is comfortable, and the like.)
(3) In many cases, the direct rays of the sun which enters from the window glass are directly irradiated onto the upper half body of the passenger, so that the passenger feels the partial heat.
In consideration of the foregoing conditions, a correlation between the comfortableness of the passenger and the change in temperature in each portion in the room was measured under various conditions. Thus, it has been found that the blowout air temperature when the passenger feels most comfortable after the room temperature was stabilized is almost unconditionally determined in correspondence to the outside air temperature and insolation amount, but the temperature at each of the representative points in the room in this state is not always constant.